His family have told police he is ordinarily a "cautious driver" and his disappearance is out of character.

Mr Mulder's mobile phone hasn't been switched on since he left home and he primarily uses cash, making his movements after leaving home difficult to track.

"It's important to note that although he indicated to his wife that he was travelling out to Esk, he's an experienced rider and at times he did often deviate from that path and could have travelled any popular motorcycle route in South East Queensland basically," Senior Sergeant Jon Kent said.